TY  - JOUR
A1  - Bernhardt, Anne
A1  - Schwanghart, Wolfgang
A1  - Hebbeln, Dierk
A1  - Stuut, Jan-Berend W.
A1  - Strecker, Manfred
T1  - Immediate propagation of deglacial environmental change to deep-marine turbidite systems along the Chile convergent margin
JF  - Earth & planetary science letters
N2  - Understanding how Earth-surface processes respond to past climatic perturbations is crucial for making informed predictions about future impacts of climate change on sediment "uxes. Sedimentary records provide the archives for inferring these processes, but their interpretation is compromised by our incomplete understanding of how sediment-routing systems respond to millennial-scale climate cycles. We analyzed seven sediment cores recovered from marine turbidite depositional sites along the Chile continental margin. The sites span a pronounced arid-to-humid gradient with variable relief and related sediment connectivity of terrestrial and marine environments. These sites allowed us to study event related depositional processes in different climatic and geomorphic settings from the Last Glacial Maximum to the present day. The three sites reveal a steep decline of turbidite deposition during deglaciation. High rates of sea-level rise postdate the decline in turbidite deposition. Comparison with paleoclimate proxies documents that the spatio-temporal sedimentary pattern rather mirrors the deglacial humidity decrease and concomitant warming with no resolvable lag times. Our results let us infer that declining deglacial humidity decreased "uvial sediment supply. This signal propagated rapidly through the highly connected systems into the marine sink in north-central Chile. In contrast, in south-central Chile, connectivity between the Andean erosional zone and the "uvial transfer zone probably decreased abruptly by sediment trapping in piedmont lakes related to deglaciation, resulting in a sudden decrease of sediment supply to the ocean. Additionally, reduced moisture supply may have contributed to the rapid decline of turbidite deposition. These different causes result in similar depositional patterns in the marine sinks. We conclude that turbiditic strata may constitute reliable recorders of climate change across a wide range of climatic zones and geomorphic conditions. However, the underlying causes for similar signal manifestations in the sinks may differ, ranging from maintained high system connectivity to abrupt connectivity loss. (C) 2017 Elsevier B.V. All rights reserved.
KW  - signal propagation
KW  - turbidity currents
KW  - Chile
KW  - sediment-routing system connectivity
KW  - Last Glacial Maximum
Y1  - 2017
U6  - https://doi.org/10.1016/j.epsl.2017.05.017
SN  - 0012-821X
SN  - 1385-013X
VL  - 473
SP  - 190
EP  - 204
PB  - Elsevier
CY  - Amsterdam
ER  -